Device for the production of fumes



Nov. 28, 1961 3,010,799

DEVICE OR THE PRODUCTION OF FUMEs Filed Jan. 5, 1959 FRHNCgS [C/IL.

ATTORNEY United StatesPatent O 3,010,799 DEVICE FOR THE PRODUCTION OF FUMES Francois Ecal, 11 Rue Relin, Beziers (Herault), France Filed Jan. 5, 1959, Ser. No. 784,985 4 Claims. (Cl. 23-252) The object of this invention is to provide an apparatus for the production of fumes by reaction of sulphur dioxide gas produced by the continuous combustion of sulphur, with ammonia gas.

According to the present invention, a fume producing apparatus, of the kind utilizing sulphur dioxide and ammonia as reagents, comprises a container for powdered sulphur, means for withdrawing powdered sulphur continuously from the container, means for mixing the powdered sulphur with combustion air and feeding the mixture to the inlet of a combustion chamber, an air blower having an air outlet, a jacket arranged about the combustion chamber and having its inlet end connected to the outlet of the air blower, the outlet ends of the combustion chamber and jacket being disposed and shaped to constitute a venturi such that passage of air through the jacket results in a lower than atmospheric pressure at the outlet end of the combustion chamber causing the combustion products to be drawn through the combustion chamber, a distributor duct disposed about the outlet end of the jacket and having part of its wall constituted by the jacket for transference of heat of combustion to the duct, said duct having in its wall a plurality of outlets forming a communication between the distributor duct and the interior of the jacket adjacent the outlet end of the combustion chamber, a reservoir for ammonia solution having an outlet, and a pipe connection between the reservoir outlet and the distributor duct.

The apparatus is of very simple construction and has a single ventilator fan. It is characterised by special air circuits, which allow of:

((1) Using a single high efliciency ventilator fan as a means for moving the air, whence ease and economy in the construction, facility in use and maintenance of the circuits and transport convenience as a result of the relatively low weight;

(1;) Easy creation of a zone of lower than atmosphere pressure which is sutficient to drive the ammonia solution into the outlet gases from the sulphur combustion furnace, which is possible despite a low pressure being used in the ammonia solution reservoir;

Heating the ammonia solution up to the point where it reaches, at the requisite rate of flow, the exit of the gases from the combustion of the sulphur, which heating is ensured without a coil, thus avoiding the risks of obstruction and counter-pressure or vapour-loo The accompanying drawing shows schematically and by way of non-limiting example a practical form of construction of the invention; this figure is a longitudinal section of the apparatus as a whole, to which has been added an outlet nozzle.

In this drawing, powdered sulphur from a container 1 is driven towards a combustion chamber 23 by air fed through an air conduit 24, the air being supplied by a blower 25. The sulphur is driven regularly and in a suitable quantity into the combustion chamber 23, which consists of successive conical parts forming venturis; then, the mixture of sulphur-air is ignited upon leaving the combustion chamber and the combustion is carried out in a furnace 8, which is of tubular form and with two end cones. The combustion in the furnace 8 produces the necessary sulphur dioxide gas for the production of the fumes.

The furnace 8 is surrounded by an external jacket which forms a chamber 9 of annular section, into which passes the greater part of the pressurized air supplied by the ventilator blower 25. This air, when going through the annular chamber 9, cools the furnace 8, keeps it at a suitable temperature, recovers the heat taken from the walls of the furnace and conveys the calories, thus recovered, to the exit 26, where it heats the distributor duct 15 and thus the ammonia solution outlets 16, thereby producing the ammonia gas at this point.

The assembly of the Walls of the furnace 8 and of the annular chamber 9 form, within the plane of the exit 26, a venturi duct which creates, at this level, a lower than atmospheric pressure. This lowered pressure ensures, on the one hand, the necessary draught through furnace 8 for driving the flame towards the exterior and, on the other hand, the sufllcient lowered pressure, at the outlets 16, for driving the ammonia solution from the reservoir 22, through the pipe 14 and to the distributor duct 15 and consequently, to the aforesaid outlets 16; this layout ensures a preheating of the ammonia solution before it comes out from the aforesaid outlets .16, at which point it is atomized by the draught of air coming from the exit of the chamber 9 and consequently, it is projected in fine drops into the hot sulphur dioxide gases which escape from the furnace 8. The ammonia gas is thus released almost instantaneously and comes into immediate reaction with the sulphur dioxide, forming an impalpable powder of sulphite and sulphate of ammonia which, on leaving the nozzle of the device, forms the cloud of fumes which is required.

In order to further improve the yield of the appliance and to ensure a total evaporation of the ammoniaso-lution, the appliance can be usefully completed, at its exit, by a Wide nozzle 27, in the form of a truncated pyramid with a triangular base with two large sides and a small side; the two large surfaces of this nozzle are heated by the hot gases emerging from the appliance and are contacted by any residual droplets of ammonia solution, ensuring that they are evaporated. This contact can be increased by fixing, on the two large surfaces of the nozzle, baffies 28 for increasing the contact surface. The mouth of the nozzle is spread out in a horizontal manner so as to increase this contact surface to the greatest posible extent; furthermore, it is organized in such a manner that its exit surface, in the direction perpendicular to the ejection direction of the fumes, is such that it ensures a flow of ejection of the gases which is practically uniform over the entire length of the mouth, so as to ensure the homogeneity of the chemical reaction without the use of vertical partitions for distributing the gase, which partitions would cut the exit cone in a longitudinal manner and which would risk causing collecting up of the crystals which were formed.

I claim:

1. A fume producing apparatus, utilizing sulphur dioxide and ammonia as reagents, comprising a container for powdered sulphur, means for withdrawing powdered sulphur continuously from the container, means for mixing the powdered sulphur with combustion air and feeding the mixture to the inlet of a combustion chamber, an air blower having an air outlet, a jacket arranged about the combustion chamber and having its inlet end connected to the outlet of the air blower, the outlet ends of the combustion chamber and the jacket being disposed and shaped to constitute a venturi such that passage of air through the jacket results in a lower than atmospheric pressure at the outlet end of the combustion chamber causing the combustion products to be drawn through the combustion chamber, a distributor duct disposed about the outlet end of the jacket and having part of its wall constituted by the jacket for transference of heat of combustion to the duct, said duct having in its wall a Patented Nov. 28,1961

a V p 3 plurality of outlets forming a communication; between the distributor duct and the interior of the jacket adjacent the outlet end of the combustion chamber, a reservoir for ammonia solution having an outlet, and a pipe connection between the reservoir outlet and the distributor duct.'

2. A fume producing apparatus, utilizing sulphur dioxide and ammonia as reagents, comprising a container for powdered sulphur with a base outlet, an air blower having an air outlet, a first air feed conduit leading from the outlet of the blower past the base outlet of the container for continuous withdrawal of powdered sulphur and feeding of the mixture of air and sulphur to means for introduction of combustion air, a combustion chamber;

receiving the mixture of sulphur and combustion air,

a jacket arranged about the combustion chamber, a second air feed conduit connecting the outlet of the blower to the inlet end of the jacket, the outlet ends of the com- 1 2, a third air feed conduit connected between the jacket and the reservoir to permit entry of air as ammonia solution is withdrawn therefrom.

4. In a fume producing apparatus, as claimed in claim 1, an outlet nozzle forming an extension of the jacket beyond its outlet end and including baffies on its internal wall to absorb heat from-the'combustion products and vaporize any unreaoted ammonia solution passing through the nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 858,640 Welles July 2, 1907 1,358,084 Leigh Nov. 9, 1920 1,362,559 Clousten Dec 14, 1920 1,720,742 Mullen July 16, 1929 2,352,677 Anderson et a1. July 4, 1944 2,828,158 Patterson Mar. 25, 1958 

1. A FUME PRODUCING APPARATUS, UTILIZING SULPHUR DIOXIDE AND AMMONIA AS REAGENTS, COMPRISING A CONTAINER FOR POWDERED SULPHUR, MEANS FOR WITHDRAWING POWDERED SULPHUR CONTINUOUSLY FROM THE CONTAINER, MEANS FOR MIXING THE POWDERED SULPHUR WITH COMBUSTION AIR AND FEEDING THE MIXTURE TO THE INLET OF A COMBUSTION CHAMBER, AN AIR BLOWER HAVING AN AIR OUTLET, A JACKET ARRANGED ABOUT THE COMBUSTION CHAMBER AND HAVING ITS INLET END CONNECTED TO THE OUTLET OF THE AIR BLOWER, THE OUTLET ENDS OF THE COMBUSTION CHAMBER AND THE JACKET BEING DISPOSED AND SHAPED TO CONSTITUTE A VENTURI SUCH THAT PASSAGE OF AIR THROUGH THE JACKET RESULTS IN A LOWER THAN ATMOSPHERIC PRESSURE AT THE OUTLET END OF THE COMBUSTION CHAMBER CAUSING THE COMBUSTION PRODUCTS TO BE DRAWN THROUGH THE COMBUSTION CHAMBER, A DISTRIBUTOR DUCT DISPOSED ABOUT THE OUTLET END OF THE JACKET AND HAVING PART OF ITS WALL CONSTITUTED BY THE JACKET FOR TRANSFERENCE OF HEAT OF COMBUSTION TO THE DUCT, SAID DUCT HAVING IN ITS WALL A PLURALITY OF OUTLETS FORMING A COMMUNICATION BETWEEN THE DISTRIBUTOR DUCT AND THE INTERIOR OF THE JACKET ADJACENT THE OUTLET END OF THE COMBUSTION CHAMBER, A RESERVOIR FOR AMMONIA SOLUTION HAVING AN OUTLET, AND A PIPE CONNECTION BETWEEN THE RESERVOIR OUTLET AND THE DISTRIBUTOR DUCT. 